API Evangelist enhancements — Paubox Email API

overlay: 1.0.0
info:
  title: API Evangelist enhancements — Paubox Email API
  version: 1.0.0
extends: ../openapi/paubox-email-api-openapi.yaml
x-generated: '2026-08-26'
x-method: generated
x-source: >-
  Derived from https://docs.paubox.com/email-api/errors,
  https://docs.paubox.com/email-api/limits and
  https://docs.paubox.com/email-api/webhooks — documented behaviour the provider
  publishes in prose but did not declare in the OpenAPI document. Applied as an overlay so
  the harvested spec stays byte-identical to what Paubox serves.
actions:
  - target: $.info
    update:
      x-status-page: https://status.paubox.com/
      x-support: https://support.paubox.com/
      x-community: https://github.com/Paubox/community/discussions
      x-idempotency-supported: false
      x-error-format: vendor-json
      x-rfc9457: false
      x-date-format-requests: RFC 2822
  - target: $.info
    update:
      x-undocumented-status-codes:
        note: >-
          The provider documents these on /email-api/errors but declares them on no
          operation in this specification, so a generated client will not model the
          retryable cases.
        codes: [403, 422, 429, 502, 503, 504]
  - target: $.paths['/messages'].post
    update:
      x-reversibility:
        reversal: null
        window: null
        note: >-
          No unsend, recall or void operation exists. Delivery is irreversible from the
          moment this call returns, and there is no idempotency key, so a retry sends a
          second email.
      x-rate-limits:
        max_recipients_per_message: 100
        max_attachment_bytes_total: 52428800
        docs: https://docs.paubox.com/email-api/limits
      x-common-400-causes:
        - Sender domain not verified
        - Missing data.message.headers.subject
        - Empty data.message.recipients
        - Attachment content is not valid base64
        - Neither text/plain nor text/html present in data.message.content
  - target: $.paths['/bulk_messages'].post
    update:
      x-reversibility:
        reversal: null
        window: null
      x-batch-guidance:
        recommended_max: 50
        ordering: >-
          Source tracking IDs are returned in the same order as the messages array; zip
          them against the input positionally.
        docs: https://docs.paubox.com/email-api/limits
  - target: $.paths['/message_receipt'].get
    update:
      x-agent-note: >-
        The only way to confirm a send after the fact. Use this before retrying a send
        whose outcome is unknown, to avoid a duplicate delivery.
  - target: $.paths['/dynamic_templates/{id}'].delete
    update:
      x-reversibility:
        reversal: createDynamicTemplate
        window: null
        note: >-
          Not a true restore — the template must be re-uploaded and receives a new ID, so
          anything referencing the old ID stays broken.
  - target: $.components.securitySchemes.PauboxToken
    update:
      x-key-issuance: Per verified sending domain, from the Paubox dashboard; displayed once.
      x-rotation: Multiple concurrent active keys per domain are supported; create before revoking.
      x-docs: https://docs.paubox.com/email-api/authentication